Mobile recirculation grill with plenum and diffuser

ABSTRACT

A recirculation grill that includes a cooktop supported by a stationary frame. The grill includes an intake aperture defining a plurality of slats configured for receiving smoke from the cooktop; a waste tray compartment connected to the trough for receiving waste and grease and having a drawer for removing and cleaning; an interior plenum configured to create a vacuum force to pull air and smoke from the cooktop into the intake aperture; a diffuser positioned over the trash compartment and extending downwardly and outwardly; a tunnel configured to receive air flow from the plenum; and a blower housing enclosing a blower fan configured for pulling air and smoke from the cooktop into the intake aperture and through the plenum. The intake aperture, the plenum, and the blower are configured to achieve 100% visible smoke capture.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.62/884,014 filed Aug. 7, 2019, which is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to the field of indoor grillsand cook tables and in particular, recirculation grills/tables.

DESCRIPTION OF RELATED ART

Indoor grilling for restaurants and private use is known in the art.Cooking food generates smoke. Traditionally, indoor cooking with eitherelectric or gas as a power source requires ventilation of the smoke.This often means installation of expensive, stationary, and robustventilation systems like fume hoods and the like. The use of fume hoodsis a major burden on a heating ventilation and air conditioning (HVAC)system. These overhead hoods must be physically placed directly over acooking surface and despite their physical position, they still fail toachieve significant smoke capture. As a result, exposure to smells andinhalation of the resulting smoke is common for those in the vicinity ofthese systems. This also causes odor pollution. The need for properventilation further limits the flexibility, innovation and design of acorresponding grill or cooking surface.

In traditional Japanese steakhouses or Teppanyaki restaurants, thegrills occupy a significant amount of surface area of a given floorspace. The grills are fixed and stationary in order to accommodate thecorresponding overhead ventilation hood system. This restricts arestaurant's ability to be creative and accommodate a variety of styles,seating arrangements, and overall design. Moreover, if the ventilationis not perfect, customers often complain of odor contamination andpenetration of their clothes thereby ruining the dining experience.These indoor grills are difficult to clean and maneuver since many ofthe structural components are fixed to satisfy fire and safety coderequirements.

Indoor recirculation grills are known. These grills and cooktops aredesigned in a way that does not require an overhead ventilation and hoodsystem. However, the safety certification required to operate thesegrills commercially is typically governed by UL and/or ETL standards.The UL/ETL certification requires 100% capture of smoke along with firesafety response and electronic and mechanical shutdown. This can bedifficult to achieve when the size of a cooking unit is reduced.

Despite other attempts to solve the problems associated with existinggrills, none of these teach or suggest a material and/or method havingthe benefits and features of the present disclosure.

SUMMARY

The present disclosure provides for a recirculation grill including: (a)a cooktop supported by a stationary frame; (b) an intake aperturedefining a plurality of slats configured for receiving smoke from thecooktop; (c) a waste tray compartment connected to the trough forreceiving waste and grease and having a drawer for removing andcleaning; (d) an interior plenum configured to create a vacuum force topull air and smoke from the cooktop into the intake aperture; (e) adiffuser positioned over the trash compartment and extending downwardlyand outwardly; (f) a tunnel configured to receive airflow from theplenum; and (g) a blower housing enclosing a blower fan configured forpulling air and smoke from the cooktop into the intake aperture andthrough the plenum. The intake aperture, the plenum, and the blower canbe configured to achieve 100% visible smoke capture. The plenum forms anopen space configured to allow airflow to expand, cool, and directairflow from the intake aperture to the tunnel. In an example, theplenum defines segmented side walls with downward ramp sectionsconfigured to collect grease at a bottom section of the plenum. Theplenum can be configured to allow at least 18 inches of distance fromthe cook surface before contacting a first filter.

In an example, the diffuser is configured to direct airflow in twoopposite outward directions. The diffuser can include a centerhorizontal section positioned between two opposed downwardly rampedsections extending away from the center section towards an outer plenumwall and down at an angle configured to direct airflow away and downwithin the plenum. In another example, the diffuser includes verticalend sections connected to the opposed ramped sections configured todirect airflow down to a lower section of the plenum. The diffuser canbe formed of metal such as stainless steel. In yet another example, theplenum is configured to allow large grease particles in the air enteringthrough the intake aperture to condense and drop out of the air and formalong the plenum walls, and wherein the plenum walls are angled towardsa grease trap positioned at a bottom section of the grill.

The present disclosure provides for a grill wherein the plenum walls arecurved. The plenum is configured to form an upper and lower aircompartment configured to form a vacuum effect at the intake aperture.The intake aperture can be configured to form enough surface area toensure 100% visible smoke capture. The trash compartment is positionedthrough the plenum and the diffuser forms a top portion of the trashcompartment. The trough is an elongated trough extending most or all ofthe length of the cooktop and is positioned below the intake aperture.

The present disclosure provides for a recirculation grill that furtherincludes a push air duct coupled to a push air blower and a push airaperture operable for trapping visible smoke from an opposite side ofthe cooktop over the cooktop and directing it to the intake aperture. Inan example, the tunnel housing can include a wool baffle filter and acombination disposable filter having a minimum efficiency reportingvalue (MERV) filter and a carbon filter. The blower fan can beconfigured for adjusting velocity in response to a variable fan driveand control process, wherein the blower is configured to pull air andsmoke from the cooktop into the intake aperture and through the plenum.

The present disclosure further provides for a recirculation grill thatincludes a mobile platform for supporting the blower housing and tunneloperable for slidably engaging with a stationary frame that supports thecooktop, wherein the mobile and stationary frames are modular framesformed of modular frame segments. The grill can further include acontroller coupled to heating elements, the blower fan, a plurality ofairflow and temperature sensors positioned within the plenum and tunnel,and a safety system. The controller is configured to monitor the blowerfan and performance of any filters within the tunnel and activate thesafety system if certain air velocity or temperature thresholds aresurpassed.

For purposes of summarizing the disclosure, certain aspects, advantages,and novel features of the disclosure have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any one embodiment of the disclosure. Thus,the disclosure may be embodied or carried out in a manner that achievesor optimizes one advantage or group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein. The features of the disclosure which are believed tobe novel are particularly pointed out and distinctly claimed in theconcluding portion of the specification. These and other features,aspects, and advantages of the present disclosure will become betterunderstood with reference to the following drawings and detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures which accompany the written portion of this specificationillustrate embodiments and method(s) of use for the present disclosureconstructed and operative according to the teachings of the presentdisclosure.

FIG. 1A illustrates a top view of a recirculation grill of the presentdisclosure with an outer housing.

FIG. 1B illustrates a front view of the recirculation grill of FIG. 1A.

FIG. 1C illustrates an isometric perspective view of the recirculationgrill of FIG. 1A.

FIG. 1D illustrates a side view of the recirculation grill of FIG. 1A.

FIG. 2A illustrates a top view of the recirculation grill of FIGS. 1A-1Dwithout an outer housing exposing a flow tunnel with blower housing andblower fan.

FIG. 2B illustrates a front view of the exposed recirculation grill ofFIG. 2A.

FIG. 2C illustrates an isometric perspective view of the exposedrecirculation grill of FIG. 2A.

FIG. 2D illustrates a side view of the exposed recirculation grill ofFIG. 2A.

FIG. 3 is an exploded view of a recirculation grill of the presentdisclosure.

FIG. 4A illustrates a top view of a recirculation grill having anelongated trough with interior components exposed and pulled out from ahousing via a mobile platform.

FIG. 4B illustrates an isometric perspective view of the exposedrecirculation grill of FIG. 4A.

FIG. 5A illustrates a plenum of an interior portion of the recirculationgrill of the present disclosure.

FIG. 5B illustrates a diffuser according to the present disclosure.

FIG. 6A illustrates a top view of a mobile platform extended for usewith a recirculation grill having an outer housing.

FIG. 6B illustrates a front view of the recirculation grill with themobile platform extended of FIG. 6A.

FIG. 6C illustrates an isometric perspective view of the recirculationgrill with the mobile platform extended of FIG. 6A.

FIG. 6D illustrates a side view of the recirculation grill with themobile platform extended of FIG. 6A.

FIG. 7A illustrates an exposed side view of the mobile platform of FIG.6A having modular frame segments.

FIG. 7B illustrates connector pieces of the modular frame of the mobileplatform of FIG. 7A.

FIG. 7C illustrates a modular bracket of the mobile platform of FIG. 7A.

FIG. 7D illustrates an example side view of the modular brackets of FIG.7A.

FIG. 8A illustrates a top view dining surface design associated with arecirculation grill of the present disclosure.

FIG. 8B illustrates an isometric perspective view of the recirculationgrill of FIG. 8A.

FIG. 9A illustrates a front view of a baffle filter for use with arecirculation grill of the present disclosure.

FIG. 9B illustrates an exploded side view of the components of thebaffle filter of FIG. 9A.

FIG. 9C illustrates an isometric perspective view of the explodedcomponent view of FIG. 9B.

FIG. 9D illustrates a front view of a combination filter for use with arecirculation grill of the present disclosure.

FIG. 9E illustrates a side view of the combination filter of FIG. 9D.

FIG. 9F illustrates an isometric perspective view of the combinationfilter of FIG. 9D.

FIG. 10 is a flow chart associated with a variable fan drive (“VFD”) foruse with a recirculation grill of the present disclosure.

FIG. 11A illustrates an isometric perspective view of a recirculationgrill having a baffle filter positioned at an angle within a tunnel ofthe recirculation grill of the present disclosure.

FIG. 11B illustrates a side view of the recirculation grill of FIG. 11A.

The various embodiments of the present disclosure will hereinafter bedescribed in conjunction with the appended drawings, wherein likedesignations denote like elements.

DETAILED DESCRIPTION

The present disclosure provides for a recirculation grill having atleast one or more of the following features: (i) a diffuser and aninterior plenum operable for improved airflow into a tunnel and greasecontrol; (ii) a waste trough extending the entire or most of a length ofa cooking surface and positioned beneath an aperture; (iii) a mobileplatform for maneuvering and improved access to interior components of acooking unit for cleaning and repair; (iv) a variable fan drive (VFD)for improved efficiency and control of airflow through a filter; and (v)a combination filter operable for improvement of filter waste, cleaning,and replacement. The present disclosure provides for a recirculationgrill/table that can be mobile and that satisfies specific requirementsin compliance with UL/ETL safety standards. Improvements over priorgrills were made that are related to ease of use/maintenance, efficientheating characteristics, and a low level of sound/vibration to notdisrupt the dining experience. This included a grill/table that ismodular which can be disassembled effectively for shipping andtransportation.

The terms “grill” and “table” can be used interchangeably in theindustry and throughout the description. Generally, a commercial kitchenor teppanyaki style restaurants will have one or more grills having aflattop cook surface heated by a plurality of electronic or gas-poweredburners connected to control knobs for adjusting cooking temperature.The grill/table includes internal components positioned below the cooksurface. The grill/table can include an outer housing sized and shapedto protect and conceal internal components. If the grill/table is mobileor provided in the restaurant seating area where customers are withinits proximity, additional safety precautions are required.

Referring to FIGS. 1A-7D, an example cooking unit or recirculation grillor table 100 is shown. In this example, grill 100 includes a cooktop 110positioned relatively flat above an interior portion of the grill.Cooktop 110 can be made from any material sufficient for cooking andease of cleaning. In this example, the cooktop 110 is fabricated as asingle plate made from stainless steel. Cooktop 110 can define arectangular geometry having a length “L” along a longer side and a width“W” along a shorter side. A user or cook/chef can access and managecooking of food at a front view position along length L. For ateppanyaki style restaurant where customers are exposed and watching thecooking of their food in close proximity, patrons or customers can sitalong a perimeter along the width W and opposite side from the frontview. This is often desired as the experience of witnessing the cookwork is a significant part of the entertainment and attraction of theserestaurants.

Recirculation grill 100 includes interior components that support thecooktop 110 and make possible smoke capture resulting from cooking. Asshown in FIG. 1, the grill 100 is enclosed by sidewalls 115 and frontface cover 116 and a back wall (not shown) thus forming an outerhousing. These walls enclose the interior components for safety andaesthetic purposes and can also serve as a muffler to limit, reduce,eliminate unwanted noise. Positioned along cover 116 is a baffle filterdoor 118 that is removable to allow access to tunnel 120 which housesone or more filters. In an example, an optional controller 122 ispositioned along cover 116 that allows a user control over heating ofcooktop 110, turning the grill 100 on and off, and providing basicdiagnostic data which is viewable on a corresponding screen. In anexample, the controller 122 includes touch screen control andcompatibility along with a digital display. In a further example,controller 122 can be programmable and include artificial intelligenceand smart adaptability to adjust for specific uses to extend or improvegrill efficiency and performance. This can include adjusting for hotzones associated with the cook surface and environmental conditionsalong with degradation of certain components.

The interior components of grill 100 include a tunnel 120 and a blowerhousing 121. The tunnel 120 serves as a filter housing for holdingfilters operable to filter smoke and airflow that is pulled from cooktop110. As food is cooked on cooktop 110, smoke and exhaust are pushed byair that is pushed through push air duct 119 and pulled through anintake aperture 112. The smoke/air generated during use of grill 100 iscontaminated with grease and food particles and must be filtered beforereleased back out of grill 100. Tunnel 120 encloses filters which ofteninclude a baffle filter and secondary filters (See FIGS. 9-11). Push airduct 119 is connected to a push air blower 128, which directly pushesair out of the push air aperture 129. Push blower 128 generates lowspeed air that is pushed across the cooktop towards intake aperture 112.This forms an air curtain over the cooktop 110. The air curtain incombination with a pull blower within blower housing 121 prevents aircontamination and allows for 100% visible smoke capture.

Blower housing 121 encloses a blower fan 123 that pulls air from cooktop110. The blower must be strong enough to pull air at enough velocityfrom the cooktop 110 through intake aperture 112, through a plenum 150,into tunnel 120 where the air is filtered before being pulled throughblower fan 123 and out of grill 100. This air can be referred to as“recirculated air”. The recirculated air is pushed down and out throughthe floor to exit at the feet of the user. In an example, a louveredvent 127 is positioned towards the front of grill 100 to guide the airout and downward as it exits. In an example, blower fan 123 includes aninlet ring that funnels air into the blower to increase efficiency. Theblower fan includes a backwards curved centrifugal fan that creates theairflow needed to capture smoke.

To heat cooktop 110, a plurality of electrical heating elements 126 arepositioned directly underneath cooktop 110. In this example, threeheating elements 126 are provided to allow for cooking or heating zoneson top of cooktop 110. This allows a user a variety of ways to managecooking food by creating different temperatures across the surface. Forexample, one zone can be designated for warming rice and vegetableswhile another zone can be at a much higher heat for cooking meats andfish. The heating elements 126 are electrically coupled to a powersource (not shown) for delivering heat to the cooktop 110 and controlnobs (not shown) for manually controlling cooking surface temperature.In another example, digital and smart controls are employed. Gas canalso be used as a heat source and is within the scope of thisdisclosure. Fire suppression nozzles 114 are positioned adjacent theintake aperture 112 and pointed towards the cooktop 110. This is asafety measure that releases fire suppression chemicals when triggeredby a failsafe safety mechanism. Safety compliance requires the presenceand function of nozzles 114 along with corresponding sensors throughoutthe interior of grill 100. The safety sensors are configured to triggerthe nozzles 114 when predetermined temperature and or pressurethresholds are surpassed.

Grill 100 further includes a splash guard 113 positioned along aperimeter of the cooktop 110. This splash guard 113 is configured toreduce and prevent grease and food from falling or being pushed off thecooktop 10. This is especially helpful in a restaurant setting wherecustomers are sitting within close proximity to the cooking surface.

Trough

In an example, grill 100 includes an elongated trough or a “grease”trough 125 which is configured to extend length L of the cooktop 110. Inan example, the cooktop 110 is 48 inches along length L and trough 125extends most of or the entire length L. Trough 125 is formed within anopening along a front face 116. This allows a user to push waste andfood through the opening and have it captured within the trough 125. Theintake aperture 112 is positioned directly above trough 125 and hasopenings or slats 152 along a backside to capture smoke and exhaust fromthe cooking surface. Additional grease and particles trapped in the airthat is captured by the aperture 112 can be captured in the trough 125.The waste captured in trough 125 is pushed to a trash compartment 111which is a drawer that can be opened from the front cover 116 of grill100. Trash drawer 111 collects food scraps and grease that is pushedinto the trough by the user. Trough 125 allows for a shorter cooksurface relative to the aperture 112 along width W, thus allowing theair curtain to fully prevent contaminated air from escaping from thecooktop surface. Since trough 125 extends along length L, it is easierfor a user to eliminate waste from the cooktop 110. Trough 125 includesa downward ramp that allows waste to flow towards trash drawer 111.

Additional interior components of grill 100 include an electrical box124 which can be positioned next to blower housing 121 and houseselectronic components and power connectors for most or all theelectrical parts of grill 100. This includes the blowers, heatingelements, controller, and sensors. A fire tank 140 carries firesuppression agent which delivers the agent to the nozzles 114 whentriggered through fire piping 141. In this example, the fire tank 140 ispositioned on an opposite side of blower housing 121 as compared theelectrical box 124. A system release module 142 can also be providedwhich is a mechanical system that releases fire suppression agent whentriggered. Both sensor and mechanical safety mechanisms are required forUL/ETL compliance.

Plenum and Diffuser

With specific attention to FIG. FIGS. 5A and 5B, the present disclosureprovides for a plenum 150 which defines an open space structureconfigured to encourage and promote efficient airflow from the intakeaperture 112 to the tunnel 121. The plenum 150 connects the aperture 112to the tunnel 121. This is the initial route air follows as it isdirected towards the filtration system housed by tunnel 121. The plenumutilizes a diffuser 151 to satisfy a safety requirement of 18 inchesfrom the cooking surface (cooktop 110) before contacting a first filterby forcing air to move around the diffuser 151. Diffuser 151 isconfigured to form a structure that ramps downwardly and outwardlytowards plenum walls 153. In this example, the diffuser includes acenter section 1501 that relatively flat or horizontal and two opposedramped sections 1502 that angle down and away from a plane A-A definedby the center section 1501. In an example, the ramped sections 1502extend towards plenum walls 153 of the outer housing of the table tocause airflow away from the center section 1501. The diffuser canfurther include vertical end sections 1503 to allow the diffused air toflow down to the lower section of plenum 150.

In an example, the diffuser 151 is formed of metal such as stainlesssteel such as 304 or 316 or the like. Various sections can be weldedtogether. When in use, air enters through intake aperture 112, hitsdiffuser 151, which splits the air to move away in at least twodifferent directions along sections 1502 towards side walls 115. Thephysical presence formed by the diffuser 151 forces the air out towardsplenum walls 153 before moving down towards tunnel 121. Along the way,as the space volume of the plenum increases, the air is expanding andthus rapidly cooling which forces larger particles to drop from the airprior to being filtered. This serves as a prefiltering of the smoke orwhatever gas is recirculated through grill 100. This diffused air mustmake a sharp turn around the diffuser 151, which causes excess grease tosling to a bottom section of the plenum 150 where it will drain to agrease tray 154. As grease laden air passes through the plenum 150,grease naturally condenses onto the outermost walls 153 due to a coolertemperature of the metal. In an example, a bottom section of plenum 150is angled downward along drainage sections 1504 of walls 153 to allowgravity to drain the grease particles to grease tray 154.

In this example, the geometry of the plenum walls 153 is segmentedshowing sharp connection points rather than a smooth curve. Althoughboth are contemplated and within the scope of this disclosure, asegmented curve design provides ease of manufacturing since the segmentscan be welded together. The plenum walls 153 are configured to directand encourage airflow and grease down towards the bottom section ofplenum 150.

The diffuser 151 effectively forms two air compartments, an upper plenum155 above the diffuser 151 and a lower plenum 156 below the diffuser151. These air compartments create a larger ratio of the compartmentopening to the cubic volume inside the compartment. A ‘vacuum’ effectresults that is necessary for capture at the intake aperture 112 togenerate the air velocity necessary for 100% or near 100% visible smokecapture. The surface area across intake aperture 112 creates an airratio vs. velocity of the air and the volume of air. This is balancedwithin the geometry of the plenum sidewalls 153 to ensure 100% visiblesmoke capture for a given size of the grill 100. Changing the surfacearea of the intake aperture 112 allows for manipulating the velocity andwith volume change by changing the shape of the plenum walls 153, thevacuum effect can be manipulated. As volume size is decreased, velocityincreases. However, an increased volume creates more demand on theblower requirement and thus the filters. Accordingly, the balance of thesize and shape of the plenum 150 should be optimized to ensuresufficient blower requirements and smoke capture.

The trash drawer 111 positioning should accommodate the spacerequirement for plenum 150 as the plenum encompasses the entirety of thefront portion of the table 100. Accordingly, the trash drawer 111 doesnot fit directly below the cooktop 110 like existing indoor cook tables.In this example, the trash drawer 11 is placed in the center of theplenum 150, extending through the plenum 150 to reach the underside ofthe cooktop 110. This utilizes dead space caused by the diffuser 151 tominimize the effect of blocking airflow. In this example, diffuser 151forms a top portion of drawer 111.

Platform Design

The present disclosure further provides for a mobile platform operableto allow for efficient and effective maneuvering of table 100 and accessand cleaning of the internal components. In this example, the mobileplatform includes a stationary frame 130 which forms the structure forholding the cooktop 110 and some of the internal components. Stationaryframe 130 is formed of modular frame segments 230 that define a mountingslot 231 that extends a length of the frame segment 230. In thisexample, each modular frame segment 230 defines a relatively squarecross section and can be cut to any desired size. In an example, theframe segments 230 are fabricated from aluminum or any material operablefor holding table 100 and its components. Stationary frame 130 includeshorizontal frame segments 130 and vertical frame segments 133. In thisexample, the platform further includes wheels 117 which can be casterwheels or the like. The wheels extend down from horizontal framesegments 130 and allow for manual maneuvering of the entire table 100along a floor or flat surface. This allows for desired mobility of eachtable 100 unit which improves cleaning, design, access, etc.

Stationary frame 130 serves as a base frame. Mobile frame 131 connectswith stationary frame 130 and is operable to slide in and out withinstationary frame 130. In a closed configuration as shown in FIG. 1, themobile frame 131 is entirely positioned within stationary frame 130 andunderneath cooktop 110. In an open position, the internal components canbe pulled out from the outer housing and exposed, like FIGS. 3, 4A, 4B,6A, 6C, 6D, and 7A. In these examples, the mobile frame 131 slides outand extends to allow access to internal components. Mobile frame 131supports ductwork for the fire system, the tunnel, and the blowerhousing. In another example, the electrical box is further positioned onthe mobile frame 131. Mobile frame 131 can be constructed of the modularframe segments 230 just like stationary frame 130. In this example,mobile frame 131 further connects to a sliding drawer 132 that allowsfor moving the mobile frame 131 to slide in and out of a guiding track.

Each frame segment 230 can be capped at each end by a connector piece232. In this example, connector 232 forms four protrusions 233 thatdefine a channel 234 there between. The channel 234 allows the connector232 to mount and connect to any other modular frame segment 232 byengaging channel 231. Accordingly, a plurality of frame structures canbe formed and designed for mounting and holding a table 100 and anycorresponding components. This allows for improved customization anddesign.

In an example, the platform design consists of two parts: the mobileplatform 131, and the stationary frame 130. The mobile platform 131 isattached to the stationary frame 130 by slides on either side of thetable 100 along width W. When slidably separated, the stationary frame130 supports the cooktop 110, heating elements 126, the electrical box124, thermocouples, junction box, and push air assembly 128. The mobileplatform 131 supports the blower 123, tunnel assembly 120, and firesystem components 140/141/142. In another example, the electrical box issupported with the mobile frame. With the table 100 open, access to atop portion of the tunnel 120 is easily achievable for filter access andreplacement. Moreover, the right and left side of the mobile platform,where the electrical box 124 and fire system components 140, 141, and142 sit respectively, and underneath the cooktop 110 for heating element126, maintenance is also made easier and more accessible.

Platform design allows for improved access to the internal componentsfor cleaning, filter replacement, and maintenance. Due to the 710 bsafety requirement for a minimum of 18″ and the requirement for theheight of the table, filters must be at almost ground level. To reachthis area to clean or replace filters would require crawling on theground. Also due to the need for the space on either side of the tunnelfor electrical and fire, there is no easy way to access the tunnelbehind these systems without a mobile platform as described herein.Also, fire and electrical systems would need to be accessed from floorlevel without the mobile platform of the present disclosure. The presentdisclosure provides for a table that can separate into two sections thatallow top access to the filters, electrical and fire systems.

Isolating the electrical box with the stationary frame offers animproved electrical configuration. When the box is stationary, atechnician can access most areas of the table without being able tomodify or touch the electrical box. This allows for a fixed connectionpoint of the electrical box to the other components or power supply. Theelectrical box can include two multiplexors that are connected via coilcables. The fire system connection has its own coil cable.

Fire piping, wiring between moving parts, and securement/levelingrequire optimization when utilizing a mobile platform. For fire piping,the stationary frame is moved further inwards to allow the fire pipe toextend to the plenum and reach the cooktop. This allows the fire systemto stay on the mobile platform. The wiring between moving parts wasaddressed by using curly cables that will form back to a spring likeshape when not extended. Leveling is achieved by placing the frame onleveling casters that include both the leg and the wheel. Forsecurement, the platform is attached to the frame via slides that canhandle well over the platform weight. This allows the platform to handleunforeseen circumstances where extra weight is added to the platformsuch as a person leaning on the plenum.

FIG. 8 illustrates an example table 100 having an eating or diningsurface 300 surrounding the cooktop 110. Since table 100 is mobile andportable, a variety of dining surface designs can be implemented. Inthis example, the surface 300 is relatively square. However, othergeometries are contemplated and within the scope of this disclosure suchas round and rectangle. The dining surface 300 can be mobile to movewith the table 100 or fixed to allow the table 100 to move in and outfrom the surface. It is further contemplated that a variety of materialsand designs aesthetics can be implemented for surface 300.

Filtration Design with Variable Fan Drive

Previous models struggle with high cost of ownership since labor costswere incurred to clean an Electro-Static Precipitator (ESP) filter withproper procedures and frequency. The cost of training for employees tomaintain and clean these units is relatively high. If improperlyhandled, the ESP can be easily damaged and caused to malfunction. Thepresent disclosure provides for a grill that uses passive filters. In anexample, passive filters include a MERV-style filter like a Merv15 andodor control combination filter (combo filter) and a wool baffle filter.These passive filters are disposable when the grease is fully saturatedand it is time replace. In addition, inner compartments that requirecleaning have been designed with ease of access to reduce the cleaningtime. Using passive filters can increase static pressure compared tousing an ESP. However, with a Variable Fan Drive (VFD) (see the flowdiagram of FIG. 10) that controls the blower speed, filter lifespan canbe increased. In an example, the VFD can monitor up to a 10% change inairflow per UL/ETL standard (unit shuts off if the airflow changes morethan 10%). This filter arrangement can provide for a 100% visual capturerate which must be met for the smoke capture, and less than 5 ppm (partsper million) of grease laden vapors measured at the exhaust for the EPAtesting. This creates inverse requirements: the lowest air velocity forthe proper filtration and the high air speed for capture.

Referring to FIGS. 9-11, the present disclosure provides for acombination disposable filter 500. The combination filter works inconjunction with a wool covered baffle filter 400. A variable speed fanis used rather than a constant speed fan to increase the lifespan of thefilters. The wool baffle filter 400 includes a frame 410 that holdstogether a wool insert 412 and a baffle filter 414. Baffle filter 414can be removed and washed. The wool baffle filter 400 will first catchthe large grease particulates making up most of the grease going intothe system (table 100). This wool covering 412 on the filter 400 is alsodisposable and should be replaced as needed. The remaining airbornegrease will then collect on the combo filter 500.

Combo filter 500 consists of two different filters 512 and 514 in onepackage. The first is a MERV filter 512 to collect the physical airbornegrease. The second is a carbon filter 514. This carbon filter 514 willadsorb odor producing particulates. Due to 710B requirements, arecirculating unit must shut off if the airflow changes by more than 10%and detection may be needed for every filter. The variable fan drive(VFD) can increase its rpms therefore maintaining the air velocity asthe filters get saturated. Due to the nature of MERV filters, as thefilter gets saturated, the filtration efficiency increases, so there isno risk of losing capture as the fan speed ramps up. This allows thefilters to be used for the entirety of the filter's lifespan rather thanneeding to be changed due to airflow requirements. To address thedetection, the combo filter 500 was specifically designed for user easeand to limit the amount of detection required.

Previous systems utilized an Electro-Static Precipitator or ESP. Issuesexist with an ESP related to cleaning and reliability. ESPs should behandled only by professionals for safety as it is a high voltagecomponent. Also, mishandling the ESP frequently causes damage tointernal plates/cells. When cells are bent or damaged the ESP will shortout the power pack causing the unit to fail. With the frequency the ESPmust be cleaned, it is highly likely for damage to occur when nothandled by professionals.

Another challenge for filtration involves the space given for the actualfilters. The filter efficiency relies on length of time grease laden airis passing through the filter. Two ways to achieve this are to slow downthe air or increase the depth of the filter. To accommodate this issue,the airflow is choked and the baffle filter 400 is positioned at anangle (See FIG. 11) within the tunnel 120 to increase the usable depthof the tunnel 120.

FIG. 10 illustrates a flow diagram of a variable fan drive process 600.In this example, the process 600 starts at box 610 where the airflow ismeasured by an airflow sensor. The airflow sensor generates an inputsignal at box 620. The input signal at box 620 is then received by aprogrammable logic controller (PLC) at box 630. This generates an outputsignal at box 630 which then moves to box 650 to adjust the variable fandrive (VFD). The VFD then drives the fan speed to adjust accordingly atbox 660.

Odor elimination and reduction is an issue to be addressed when workingwith recirculation grills or any indoor restaurant environment.Accordingly, in another example, a finishing filter is provided withinthe airflow pathway after the air has been cleaned by both the bafflefilter and the combination filter. This finishing filter can include afiltering material that defines a relatively large surface area tocapture and/or eliminate any remaining odor particles like fatty acidsfrom meats. In another example, the finishing filter is specificallydesigned to eliminate odors resulting from the cooking of steak/beef,seafood, poultry, vegetables, rice, and cooking oils.

The present disclosure provides for a recirculation grill/table thatutilizes a trough 125 to collect grease by draining into an interior ofthe grill 100. Trough 125 is located right in front of the intakeaperture 112, which increases the distance required for smoke capture.Thus, the aperture 112 combats this disadvantage by hanging over thetrough 125 to increase the depth of capture. In addition, the airflowcan be optimized by adjusting the filter 400/500 makeup to handle anacceptable air speed for capture while balancing the air speed to volumeratio to create a vacuum effect. Adding push air aperture 119 and pushair blower 128 on an opposing side of the cooktop 110 from the aperture112 traps air that results in additional capture and prevents it fromescaping away from the table. This causes air entrainment in thedirection of the aperture 112 assisting in capture.

Cost reduction of service can also be achieved with grills according tothe present disclosure. Previous models did not have indicators todiagnose the technical issues. For instance, an ESP generallymalfunctions caused by lack of cleaning. Without proper cleaning,extensive grease/debris is built up on the ESP and creates a path for anelectrical short. If correctional action is not taken, the powerpackenters a safety mode and causes the loss of filtration efficiency andsmoke capture. The present disclosure incorporates indicators on fuses;highlighted short circuits as well as a smart system that alerts usersvia a Human Machine Interface (HMI) screen to address specificmalfunctions and output instructions.

The present disclosure provides for a grill/table having standarddimensions that fit in line with other units for most kitchens. In anexample, a grill/table of the present disclosure fits within standardspecifications for a kitchen griddle: 30″ (H)×50″ (L)×33″ (W).

The present disclosure provides for a mobile grill/table with reducedweight and size to allow the unit to be easily moved around and throughdoors without needing additional labor. The table weight was reduced dueto elimination of a mounting plate by using cast aluminum heaters.Further, alternating from mild steel to extruded aluminum can contributeto a significant weight reduction. Extruded aluminum does not only haveadvantage of weight reduction, but also enables a modular design. Thealuminum extrusions and subsystems are removable by bolts for fieldreplacement while not requiring specialized knowledge. Hence, it mayreduce the service costs. Additionally, shipping is simplified as framescan be partially assembled.

The present disclosure provides for user-friendly features including theease of use/maintenance. Unlike a limited Automatic TemperatureController (“ATC”), the grill of the present disclosure utilizes anadvanced HMI (smart) system display that provides diagnostic informationto end-users. These messages can alert the user to replace filters,change fuses, or be aware of an active short. It reduces the significantdowntime and maintenance cost. Another advantage includes the level ofmaintenance for cleaning and filter replacement. As aforementioned inthe cost of ownership, using passive filters with a VFD eliminates theneed to clean the main active filter. As filters clog with grease, theVFD ramps up the speed of blower to a level that maintains proper airspeed and capture. This continues until the filter reaches its “end oflife cycle” and the HMI notifies the user to replace the filter.

Further, the mobile platform allows for the filtration, aperture, andfire system to be located on a mobile platform, which is housed withinthe stationary frame holding electrical system, push air, and cooktop.This allows the mobile platform to be rolled out and the filtrationtunnel and other essential systems to be easily accessible for theservice. For the filter replacement, simple steps of opening the tunneldoor, discarding the old filter, and sliding in a new filter can beeasily performed. After the safeties are properly locked and the mobileplatform resumes to its original position, the unit can turn back on andoperate.

Important aspects of a cooking appliance for the restaurant industry areits reliability and efficient heating characteristics includingheat-up/recovery speed. Common criticism of electric appliances is thatthe temperature capability often cannot measure with a gas-powered unit.Reaching and retaining sufficient heating can be a major challenge asavailable amperage has to be split between cooking and built-in hoodsystems for the recirculation. In an example, for enhanced heatingcapacities, the present disclosure provides for a 50-amp table unit soavailable amperage is increased. In an example, a clad cooktop isprovided. Clad cooktops are combinations of aluminum, steel, and otherlayered metals to promote heat-transfer characteristics. Aluminum hascharacteristics to increase the heat transfer and reduces the heatrecovery time. A casted aluminum heating assembly also covers the mostarea of the underside cooktop that creates a more even edge-to-edgeheating characteristic.

The present disclosure provides for a table with sound and vibrationreduction and canceling. For recirculating grills, a higher level ofsound and vibration are produced from the motor and airflow because ofthe blower. A high-pitched whistling noise can result and detected byair leaks/gaps from improper manufacturing process. In an example, theexhaust exits into the grill based on the concept that the increasedsize of a muffler lowers the pitch. The higher pitch sounds moreirritating than the lower of the same decibel level. Since a traditionalmuffle is not used, the grill is enclosed by a double-walled corrugatedpanel that muffles the sound produced within the grill. In addition,proper gasket can be used to secure the blower and all moving parts toproduce the lowest possible level of the sound and vibration. Theinterior wall surface of the table effectively serves as a muffle whichmay affect the exhausted air. With high volumes of exhaust air exitingthe grill underneath the frame in any direction, exhausted air isdirected to a specific area in order to control turbulence andentrainment. To achieve this, a kickplate is provided around the grillto prevent the air leakage and added louvre panels and diffusers on theplenum to direct the exhaust at a downward angle.

The present disclosure may utilize the following aspects: a mobileplatform with a stationary frame, usage of a passive filter inconjunction with a VFD to maintain the lowest possible air speed forcapture, utilizing the outer frame itself as a muffler to address soundand space concerns including a trough in front of the aperture in arecirculating system, and placing the baffle filter at an angle.

It should be noted that the steps described in the method of use can becarried out in many different orders according to user preference. Theuse of “step of” should not be interpreted as “step for”, in the claimsherein and is not intended to invoke the provisions of 35 U.S.C. § 112(f). Upon reading this specification, it should be appreciated that,under appropriate circumstances, considering such issues as designpreference, user preferences, marketing preferences, cost, structuralrequirements, available materials, technological advances, etc., othermethods of use arrangements such as, for example, different orderswithin above-mentioned list, elimination or addition of certain steps,including or excluding certain maintenance steps, etc., may besufficient.

The embodiments of the disclosure described herein are exemplary andnumerous modifications, variations and rearrangements can be readilyenvisioned to achieve substantially equivalent results, all of which areintended to be embraced within the spirit and scope of the disclosure.Further, the purpose of the foregoing abstract is to enable the U.S.Patent and Trademark Office and the public generally, and especially thescientist, engineers and practitioners in the art who are not familiarwith patent or legal terms or phraseology, to determine quickly from acursory inspection the nature and essence of the technical disclosure ofthe application.

What is claimed is:
 1. A recirculation grill comprising: (a) a cooktopsupported by a stationary frame; (b) an intake aperture defining aplurality of slats configured for receiving smoke from the cooktop; (c)a waste tray compartment connected to a trough for receiving waste andgrease and having a drawer for removing and cleaning; (d) an interiorplenum configured to create a vacuum force to pull air and smoke fromthe cooktop into the intake aperture; (e) a diffuser positioned over thewaste tray compartment and extending downwardly and outwardly towardopposite plenum walls; (f) a tunnel configured to receive airflow fromthe plenum; and (g) a blower housing enclosing a blower fan configuredfor pulling air and smoke from the cooktop into the intake aperture andthrough the plenum; wherein the waste tray compartment is positionedthrough the plenum and the diffuser forms a top portion of the wastetray compartment.
 2. The recirculation grill of claim 1, wherein theplenum forms an open space configured to allow airflow to expand, cool,and direct airflow from the intake aperture to the tunnel.
 3. Therecirculation grill of claim 1, wherein the plenum defines segmentedside walls with downward ramp sections configured to collect grease at abottom section of the plenum.
 4. The recirculation grill of claim 1,wherein the plenum is configured to allow at least 18 inches of distancefrom the cooktop before contacting a first filter.
 5. The recirculationgrill of claim 1, wherein the diffuser is configured to split and directairflow in two opposite outward directions.
 6. The recirculation grillof claim 1, wherein the diffuser includes a center horizontal sectionpositioned between two opposed downwardly ramped sections extending awayfrom the center section towards the opposite plenum walls and down at anangle configured to direct airflow away and down within the plenum. 7.The recirculation grill of claim 6, wherein the diffuser includesvertical end sections connected to the opposed ramped sectionsconfigured to direct airflow down to a lower section of the plenum. 8.The recirculation grill of claim 1, wherein the diffuser is formed ofmetal.
 9. The recirculation grill of claim 1, wherein the plenum isconfigured to allow large grease particles in the air entering throughthe intake aperture to condense and drop out of the air and form alongthe plenum walls, and wherein the plenum walls are angled towards agrease trap positioned at a bottom section of the grill.
 10. Therecirculation grill of claim 1, wherein the plenum walls are curved. 11.The recirculation grill of claim 1, wherein the plenum forms an upperand lower air compartment configured to form a vacuum effect at theintake aperture.
 12. The recirculation grill of claim 1, wherein theintake aperture, the plenum, and the blower fan, are sized and shaped toachieve 100% visible smoke capture when the blower fan and the grill arein use.
 13. The recirculation grill of claim 1, wherein the trough is anelongated trough extending most or all of the length of the cooktop andis positioned below the intake aperture.
 14. The recirculation grill ofclaim 1, further comprising a push air duct coupled to a push air blowerand a push air aperture operable for trapping visible smoke from anopposite side of the cooktop over the cooktop and directing it to theintake aperture.
 15. The recirculation grill of claim 1, wherein thetunnel housing includes a wool baffle filter and a combinationdisposable filter having a minimum efficiency reporting value (MERV)filter and a carbon filter.
 16. The recirculation grill of claim 1,wherein the blower fan is configured for adjusting velocity in responseto a variable fan drive and control process, wherein the blower isconfigured to pull air and smoke from the cooktop into the intakeaperture and through the plenum.
 17. The recirculation grill of claim 1,further comprising a mobile platform for supporting the blower housingand tunnel operable for slidably engaging with a stationary frame thatsupports the cooktop, wherein the mobile and stationary frames aremodular frames formed of modular frame segments.
 18. The recirculationgrill of claim 1, further comprising a controller coupled to heatingelements, the blower fan, a plurality of airflow and temperature sensorspositioned within the plenum and tunnel, and a safety system.
 19. Therecirculation grill of claim 18, wherein the controller is configured tomonitor the blower fan and performance of any filters within the tunneland activate the safety system if certain air velocity or temperaturethresholds are surpassed.